Hydraulic fracturing, often referred to as “fracking” in the energy industry, is a stimulation technique utilized to increase the productivity of an oil and/or natural gas well.
The fracturing process involves injecting a fluid into rock formations at a high rate and pressure in order to widen existing openings in the rocks or create new cracks in the formation. Once the cracks are created, fluid containing a particulate material, often referred to as a propping agent or “proppant,” is pumped into the newly created fractures to maintain the openings. This process allows for an easier and more efficient flow of hydrocarbons (e.g. oil and/or natural gas) through increased permeability in tight underground structures.
Hydraulic fracturing has been used with increasing frequency to improve the productivity of oil and/or natural gas wells in low permeability reservoirs. The list of raw materials previously used as proppants include: sand (the most common proppant), nut shells, aluminum and aluminum alloys, wood chips, crushed coke, granulated slag, pulverized coal, crushed rock, granules of metal such as steel, sintered bauxite, sintered alumina, refractories such as mullite, and glass beads.
As the technology associated with hydraulic fracturing has evolved and improved, those in the industry have recognized the benefit of manufacturing spherical shaped proppant bodies. Ceramic proppants in particular were manufactured with particulate material that was processed by a “dry” or “wet” manufacturing technique.
Ceramic proppants have been found to yield more consistent and efficient production than some of the more common and inexpensive proppants. Ceramic proppants have been shown to have more advantageous characteristics due to their increased strength and uniformity of size and shape. Ceramic proppants have not been utilized as commonly as others in the past because of certain limitations.
Common mineral particulates historically used in the manufacture of ceramic proppants are characterized by a high alumina content. This has caused difficulty in the manufacturing process, as many mineral particulate deposits are limited in supply and only available in certain geographical locations. The scarcity of raw materials has led to manufacturing facilities located far from the oil and/or natural gas wells on which they will be utilized, and therefore higher associated transportation costs of said proppants.
A ceramic proppant that is stronger and more efficient, with a more cost effective method of being produced, has been the desire of those in the oil and gas industry for years.